Abstract: A dish antenna structure (10) is formed from a plurality of ribs (14) which extend from near the center of the dish to its periphery, and which support antenna panels (18) between them. Each rib has an outer flexible plastic sheath having grooves (44,45) in its side edges which receive the edges of antenna panels (18) and a hollow longitudinal channel (40) within which a rigid support member (42) is fixed. The support ribs (14) and the antenna panels (18) are curved such that the anterior surface of the dish defined thereby is parabolic.
Abstract: Apparatus for an earth station antenna is disclosed herein including a parabolic dish antenna pivotally carried on an upper support post mounted for rotation about a vertical axis. Pivotal linkage interconnects the antenna with the upper support post for rotation about a horizontal axis. Power drive is carried in the upper support post for pivoting the antenna about its horizontal axis via the linkage while separate power drive operably couples between the upper support post and a stationary lower post for rotating the upper support post and the antenna about the vertical axis. The lower end of the lower support post is provided with a mounting recess for insertably receiving the terminating end of an upright mounting stanchion.
Abstract: A surface wave microwave antenna is presented in which transmission or reception of microwave energy is effected by discontinuities in a dielectric body positioned between a central feeder element and a ground plane. When used as a transmitter, the central disc propagates surface waves in the dielectric body in expanding circles; and the discontinuities in the dielectric body act as radiating or scattering sites to couple the waves to free space. When used as a receiver, the reverse will occur.
Abstract: This invention relates to an improved means of orienting parabolic dish shaped TV antennas for receiving signals from relay satellites orbiting the earth, an angle indicating means associated with antenna assembly which indicates either the angle of elevation or the complementary angle then of which is equivalent to the latitude of the antenna site plus the offset or declination angle.
Abstract: A mount for supporting a feedhorn/LNA assembly in a parabolic satellite antenna is disclosed, said mount providing a sturdy support for positioning the feedhorn/LNA assembly at the focal point of the antenna and providing means for skew adjustment of the LNA probe.
Abstract: A microstrip antenna system has a central two-dimensional array (preferably square having at least 16.times.16 elements) of integrally formed conductive dual slot microstrip radiator patches. A corporate-structured array of interconnected microstrip feedlines connects a common input/output r.f. signal feedpoint to each of the central array patches and also incorporates a fixed-angle phasing offset so as to steer the main lobe or beam of the overall radiation pattern off-center. The common r.f. signal input/output connection point is itself physically offset to one side of the overall composite of array elements. Auxiliary tapered amplitude linear arrays of dual slot patches also preferably extend on all sides outwardly from the periphery of the central array so as to reduce the side lobe amplitude and main lobe beamwidth of the overall radiation pattern.
Abstract: A portable lightweight folding parabolic reflector antenna for reception of microwave signals includes an axial waveguide tube which constitutes the main structural supporting member of the antenna, a ten- to fifteen-foot diameter dish mounted to the waveguide and a sub-reflector supported at the forward end of the waveguide. A low noise amplifier may be mounted to the rear end of the waveguide for amplification of the received signals. The folding dish includes a single sheet of resiliently elastic reflecting mesh supported by a radial framework of normally straight resiliently flexible spokes of tapering cross section. The spokes are pivotable by a lever system between a folded axial position and a deployed radial position.
Abstract: A broadband high temperature radome includes a high density outer skin layer and a low density core layer made from a ceramic material selected from the group consisting of silicon nitride and barium-aluminum silicate. Silicon nitride is sintered, reaction-sintered or chemically vapor-deposited. The outer skin has a moderate dielectric constant of about 5.0 and the core layer has a low dielectric constant of about 1.8. Both dielectric constants do not sigificantly vary at temperatures up to 1500.degree. C. Low thermal expansion of the core and skin layers are matched by the thermal expansion of a base connector constructed in a laminated form of graphite/polyimide. The thickness of the core layer to the thickness of the skin layer is given by the ratio of about 15:1 where the skin layer thickness is about 0.030 inch. Polyimide resin is used for the high temperature adhesive to adhere the connector to the core and skin layers. The core layer is impregnated with a dielectric filler, if desired.
February 2, 1981
Date of Patent:
June 30, 1987
The Boeing Company
Edward L. Koetje, Frederick H. Simpson, James F. Schorsch
Abstract: A photoresist-type chemical etching process is used to define a computer-generated flat pattern of conductors as if a complex conical spiral had been cut apart along a straight line through the apex and laid flat. The substrate in the shape of a circular sector is bent into a cone and the radial edges are joined in a seam. The split turns of the spiral are electrically interconnected across the seam.
Abstract: A horn radiator with a grooved inner surface has a mode coupler for a TE.sub.01 wave and includes four cavity resonators embedded in the grooved surface of the horn and interconnected by an annular rectangular wave guide extending around the outer surface of the horn.
Abstract: An electrically small, dual polarized, hemispherical coverage, multi-element adaptive array antenna exhibiting low VSWR and operational over an octave of bandwidth is flush-mounted with the airframe structure of high performance aircraft. The antenna is configured as a cavity type structure in the shape of a regular polygon and has a plurality of radiation elements mounted on an insulative support board, each of the elements being is connected to a respective output port for use in a multi-channel adaptive array system. The array provides broadband capability of nulling interfering sources having arbitrary polarization and spatial direction.
Abstract: An apparatus for the stable support of a structure, such as an antenna, in a fluid medium, such as the ocean. A flotation bag supporting an antenna is stabilized by the following features, which can be used individually or in combination. A partially submerged ribbon fence supported by a submerged damper skirt dissipates the kinetic energy of the flotation bag caused by the movement of the ocean and water that encroaches upon the bag. A flexible connection between the bag and the payload enables the bag and the payload to undergo limited motion without affecting each other. Thus, the bag's motion is decoupled and totally independent of the payload. The housing which supports the payload has a flooded chamber, lowering the center of mass of the apparatus. The bottom of the flotation bag is inwardly arched, moving the bouyancy away from the center of the bottom of the bag, enhancing stability and allowing the bag to float lower in the ocean, keeping the damper skirt submerged. The payload includes an r.f.
February 20, 1986
Date of Patent:
June 23, 1987
Tyler C. Robinson, Wayne J. Sula, Roger C. Larson, William J. Wallace
Abstract: A rate sensor, preferably comprised of a tuned gyro, has a generally cylindrical outer housing and an inner, large diameter rotary cylindrical support defining the gyro's rotary axis. The rate sensing apparatus is mounted in the volume between the outer housing and the rotary cylindrical support whereby the interior of the rotary cylindrical support defines a large diameter hollow for receiving and supporting apparatus, other than rate sensing components of the rate sensor. The rate sensor may be advantageously used with a homing device, the seeker apparatus of the device being mounted in said hollow. This produces a homing device with a high packing density and, as the rotary axis of the gyro gimbals and that of the seeker coincide, detrimental unbalance and unwanted increase in inertial movement is eliminated.
Abstract: A high bandwidth microwave antenna feed comprises a spigot (4) of relatively high dielectric constant protruding from a conventional hollow waveguide (3) and a generally conical member (12) of relatively low dielectric constant fitted coaxially onto, so as to expand from the protruding spigot. The base portion (2) of the conical member is silvered and constitutes a sub-reflector. In use, microwave radiation from the hollow waveguide is refracted at the spigot/conical member interface and is reflected from the sub-reflector to a facing main reflector (1). The two-part dielectric construction enables the dimensions of the sub-reflector to be reduced, thereby reducing blockage of the main reflector and increasing the bandwidth of the system.
Abstract: A radio antenna which operates over a broad frequency band, comprising a half-wave antenna tuned to a frequency beyond one cut-off frequency of the desired frequency band and a quarter-wave transformer tuned to a frequency beyond the other cut-off frequency at the other end of said band. The quarter-wave transformer acts as an impedance compensation device by canceling the reactive components of the half-wave antenna such novel reactive cancellation technique provides broadband performance while maintaining the antenna's gain and impedance characteristics.
Abstract: A backfire feed antenna has a parabolic reflector with a ring-focus at the reflector focal point comprising a dielectric waveguide having a stem portion and a cap portion with a pointed end and most of the stem portion inside a conducting tube along the axis of the parabolic reflector. The outer surface of the cap portion is concave outward and convex inward and covered with a conducting layer. A curve between a parabola and hyperbola defines the surface. The cap portion has a conical surface extending between an annular surface at the junction between the stem portion and the cap portion and an axially extending circumferential surface surrounding the conducting layer. The inside end of the dielectric waveguide is pointed.
Abstract: Improved radar reflector apparatus of the type comprising a collapsible and inflatable envelope surrounding a collapsible reflector array made of reflectors which, when the envelope is inflated, form a plurality of corner reflectors. The improvement resides primarily in the fact that each of the reflectors is mounted or suspended in the envelope by a string mounting network independently of the others.
Abstract: A polarized signal receiver waveguide assembly, or feedhorn, for receiving a selected one of linearly polarized electromagnetic signals in one waveguide of circular cross-section and for launching or transmitting the selected signal into a second waveguide, the axes of the waveguides being disposed at a right angle. The first waveguide has a closed end wall, formed as a hemispherical cavity having a hemispherical concave surface. A probe comprising a signal receiver portion disposed in a plane perpendicular to the axis of the first waveguide and a launch or transmitter portion having its axis perpendicular to the axis of the second waveguide has its launch or transmitter portion mounted in a controllably rotatable dielectric rod, such that rotation of the rod causes rotation of the signal receiver portion for alignment with a selected one of the polarized signals.
Abstract: An antenna suitable for the generation of a circularly polarized annular radiation pattern comprising a substrate spaced apart from a ground plane by a layer of dielectric material, the substrate being arranged to carry on one side thereof a conductive layer in which a plurality of radial slots is defined equiangularly disposed to extend outwardly from a central region of the substrate, and on the other side thereof a microstrip feed line arrangement via which the radial slots are arranged to be fed with microwave energy for the generation of a horizontally polarized radiation pattern and via which an edge slot defined between the peripheral edge of the layer and the ground plane is arranged to be fed with microwave energy for the generation of a vertically polarized radiation pattern whereby the horizontal pattern and the vertical pattern in combination afford the circularly polarized annular radiation pattern.
Abstract: Current-flow is suppressed on the outer surface of the horn except in a small endmost region. A reflector surrounds the horn, spaced rearwardly from the mouth. A choke used for the suppression blocks current-flow between the horn and the reflector. A high degree of uniformity of the radiation pattern over a wide forward angle is achieved.